CN105491668A - Multi-AP cooperation based interference elimination method in dense WLAN environment - Google Patents
Multi-AP cooperation based interference elimination method in dense WLAN environment Download PDFInfo
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- CN105491668A CN105491668A CN201510939127.4A CN201510939127A CN105491668A CN 105491668 A CN105491668 A CN 105491668A CN 201510939127 A CN201510939127 A CN 201510939127A CN 105491668 A CN105491668 A CN 105491668A
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W72/00—Local resource management
- H04W72/50—Allocation or scheduling criteria for wireless resources
- H04W72/54—Allocation or scheduling criteria for wireless resources based on quality criteria
- H04W72/541—Allocation or scheduling criteria for wireless resources based on quality criteria using the level of interference
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Abstract
The invention discloses a multi-AP cooperation based interference elimination method in a dense WLAN environment, mainly for solving the problems of mutual interference between access points and low system capacity in the prior art. The method comprises the following realization steps: in a communication process between a site and a current access point, other neighbor access points determining whether to send data, and if so, the neighbor access point directly sending the data and waiting for the site to replay a confirmation character; after the neighbor access point sends the data, transmitting the data to the current access point through a wired mode; the current access point, by use of a physical layer network encoding technology, performing demodulation mapping on received pollution signals and then determining an initial position of pollution by use of lead code correlation; and directly performing bit XOR after the initial position, and recovering original data from the pollution signals so as to eliminate interference signals. According to the invention, downlink service transmission of the neighbor access points and sites associated therewith is realized while the interference is eliminated, the system capacity is improved, and the method provided by the invention can be applied to a densely disposed WLAN environment.
Description
Technical field
The invention belongs to communication technical field, be specifically related to a kind of interference elimination method, being used under the WLAN environment of dense deployment is cooperated mutually by wired connection between access point AP realizes interference and eliminates, capacity.
Background technology
Along with the fast development of WLAN (wireless local area network) WLAN, the interference in WLAN makes channel utilization greatly reduce.Interference in WLAN mainly comprises interference and system in system and disturbs two large classes outward, wherein for the interference outside system, such as WLAN and existing GMS network, TD network and following LTE network are total to location or close road, especially particularly serious to the interference of WLAN with 2.3GHZ frequency range LTE; Other some equipment comprise microwave oven, cordless telephone, bluetooth etc. and also can produce interference; For intrasystem interference, as co-channel interference not only causes former access point AP throughput obviously to decline, total throughout is also on a declining curve.
Such as, for the interference problem in WLAN, concealed terminal, exposed terminal, many equipment competes the efficiency of transmission caused low and microwave, cordless telephone, bluetooth interference etc., and WLAN proposes following Anti jamming Scheme:
1. dynamic power control scheme, by controlling the visible level of access point AP to the control of access point AP transmitted power;
2. dynamic channel Adjusted Option, scans each situation such as channel seizure ratio, signal strength by access point AP, and considers the channel distribution of whole net, selects to be operated in the measured channel of matter;
3. the request proposed for concealed terminal sends RTS/ clear to send CTS scheme, before sending datagram, request transmission RTS/ clear to send CTS is used to carry out the reservation of channel alternately, occupied to other node specification channels with the form of short bag, prevent collision;
4., for the impact of exposed terminal, propose the scheme of dynamic conditioning clear channel assessment (CCA) CCA thresholding, under interference environment, by the detection of access point AP to wireless environment, suitably can adjust clear channel assessment (CCA) CCA thresholding;
5. the prioritization scheme of backoff parameter, by the parameter such as clearance D IFS, short interFrameGap SIFS, minimum competition window CWmin, maximum contention window CWmax, acknowledge character ACK between adjustment distributed frame, avoids interference.
Not very dense for the network coverage, when interference is not very serious, can be optimized by such scheme; But under the WLAN environment of dense deployment, the mutual interference between access point AP makes above-mentioned Anti jamming Scheme effect very limited.Mutually disturb between the access point AP under above-mentioned intensive WLAN environment, there is relevant solution in the last few years, reduce the transmitting power of access point AP or dynamic some access point of closedown AP on the one hand, make not exist between access point AP interference mutually or disturb very light, although this method can reduce the signal disturbing between access point AP, the number of users that single access point AP is served reduces; On the other hand when certain access point AP communicates with site STA, the access point AP time-out be disturbed communicates, until sign off, though this method effectively can avoid network conflict, causes being that the throughput of the access point AP be disturbed reduces greatly.
Summary of the invention
The object of the invention is the deficiency for above-mentioned prior art, and the interference elimination method of working in coordination with based on many AP under proposing a kind of intensive WLAN environment, with elevator system throughput.
For achieving the above object, technical scheme of the present invention comprises the steps:
(1) set up in the process communicated with current access point AP1 at transmitting station STA1, the neighboring access point AP be disturbed judges whether to send wireless data: if will send wireless data, performs step (2); If do not send wireless data, perform step (3);
(2) can neighboring access point AP judge send wireless data: if can send wireless data, then directly send data, performs step (4); If wireless data can not be sent, then perform step (3);
(3) according to existing 802.11 agreements, neighboring access point AP keeps mourning in silence, and waits for network allocation vector NAV timer then, returns step (2) after timing terminates;
(4) neighboring access point AP is in transmission data, waits for the station replies acknowledge character ACK communicated with, and receives data generation interference to current access point AP1;
(5) current access point AP1 solves the data of needs from contaminated data:
(5.1) wireless data of transmission is converted to the frame format of cable network by neighboring access point AP by the protocol conversion module of MAC layer, sends current access point AP1 to by cable network, and current access point AP1 receives and these data of buffer memory;
(5.2) current access point AP1 sends the modulation system of signal and the frame format of neighboring access point AP transmission signal according to transmitting station STA1, physical-layer network coding method is adopted to carry out demodulation mapping to the contaminated wireless data signal received, and these data of buffer memory;
(5.3) current access point AP1 is according to the lead code in the data of step (5.1) buffer memory, and in step (5.2), data cached beginning pollutes position to utilize lead code correlation detection methods to determine;
(5.4) current access point AP1 is by data-signal direct step-by-step XOR after starting to pollute position of the data-signal of step (5.1) buffer memory and step (5.2) buffer memory, from pollution signal, recover former data-signal, realize the elimination to interference.
The present invention has the advantage of two aspects:
First, the present invention, in conjunction with access controller AC, utilizes the advantage of physical layer network coding technique, by wired re-transmission to interference signal, achieves the elimination of interference signal;
Secondly, while eliminating interference, also achieve the downlink traffic transmission of neighboring access point AP site STA associated with it.The present invention can solve under intensive WLAN environment, and the problem because mutually disturbing the throughput caused to reduce between AP, improves power system capacity.
Accompanying drawing explanation
Fig. 1 is the scene graph that the present invention uses;
Fig. 2 is realization flow figure of the present invention;
Fig. 3 is the schematic diagram that the site STA of neighboring access point communication in the present invention postpones to reply ACK.
Embodiment
Referring to accompanying drawing, describe the present invention:
With reference to Fig. 1, the scene that the present invention uses is the scene of interference mutually between the many AP under an intensive WLAN environment, and it comprises three access points AP1, AP2, AP3 and three site STA 1, STA2, STA3 and access controller AC.The website that wherein the first access point AP1 is associated is the first website STA1, and the website that the second access point AP2 is associated is the second website STA2, and the website that the 3rd access point AP3 is associated is the 3rd site STA 3.Mutually disturb between these three access points AP1, AP2 and AP3.Second access point AP2 and the 3rd access point AP3 can receive the RTS frame that the first website STA1 sends to the first access point AP1, and the second access point AP2 and the 3rd access point AP3 also can receive the CTS frame that the first access point AP1 replys to the first website STA1.Second website STA2 and the 3rd site STA 3 be not in the coverage of the first access point AP1 and the first website STA1, and the first website STA1 is in the coverage of these three access points AP1, AP2 and AP3.These three access points AP1, AP2 and AP3 are received on access controller AC respectively by wired company.
With reference to Fig. 2, realization flow of the present invention is as follows:
Step 1: the second access point AP2 obtains the information that the first access point AP1 communicates with the first website STA1.
First website STA1 and the first access point AP1 adopt RTS/CTS handshake mechanism to set up and communicate, according to Fig. 1, second access point AP2 is in the communication coverage of the first website STA1 and the first access point AP1, second access point AP2 can receive the RTS frame that the first website STA1 sends to the first access point AP1, also can receive the CTS frame that the first access point AP1 replys to the first website STA1.According to the information in CTS frame, the second access point AP2 upgrades NAV timer, and records the address of the first access point AP1 and the moment D of the first transmitting station STA1 and the first access point AP1 sign off.
Step 2: the second access point AP2 sends data
In the process that the first website STA1 communicates with the first access point AP1, first the second access point AP2 judges whether application layer has data to send, if do not have data to send, then keep mourning in silence, whether wait NAV timer then rejudges afterwards has data to send; If had, now the second access point AP2 compares the size of NAV timer remaining time and given threshold value: if NAV timer is less than given threshold value remaining time, then the second access point AP2 can not send data, waits for NAV timer rejudges whether can send data again then; If be greater than or equal to given threshold value, then the second access point AP2 now can send data;
Second access point AP2 asks releasing to be mourned in silence, to start to send data to access controller AC.Second access point AP2 removes the short frame of mourning in silence by there being alignment access controller AC to send a request, if now there has been other neighboring access point to ask releasing to be mourned in silence to AC, then access controller AC replys the second access point AP2 and do not allow releasing to mourn in silence; If no, then reply permission releasing to mourn in silence; After second access point AP2 removes and mourns in silence, start to send data to the second website STA2, be greater than NAV timer remaining time when the second access point AP2 sends the data time used, then send data according to existing 802.11 protocol segmentations; When being less than or equal to NAV timer remaining time, directly sending data, in the data that the second receiving station STA2 sends, comprising the sign off moment D of record in step 1.
After second website STA2 receives data, reply acknowledge character ACK to the second access point AP2.
With reference to Fig. 3, the process that the second website STA2 postpones to reply ACK is as follows:
After second website STA2 receives data, by these data of demodulation, record the moment D of the first website STA1 and the first access point AP1 sign off, record the moment E oneself completing data receiver simultaneously, according to above two parameters, the timing calculating NAV timer in the second website STA2 is D+SIFS-E, and SIFS is short frame time interval here, and this timing is time of delay when replying ACK;
Second website STA2 replys acknowledge character ACK to the second access point AP2 after waiting for that NAV timer then.
More than describing is only instantiation of the present invention, does not form any limitation of the invention.Obviously for those skilled in the art; after having understood content of the present invention and principle; all may when not deviating from the principle of the invention, structure; carry out the various correction in form and details and change, but these corrections based on inventive concept and change are still within claims of the present invention.
Claims (6)
1. under intensive WLAN environment based on the interference elimination method that many AP are collaborative, it is characterized in that, comprising:
(1) set up in the process communicated with current access point AP1 at transmitting station STA1, the neighboring access point AP be disturbed judges whether to send wireless data: if will send wireless data, performs step (2); If do not send wireless data, perform step (3);
(2) can neighboring access point AP judge send wireless data: if can send wireless data, then directly send data, performs step (4); If wireless data can not be sent, then perform step (3);
(3) according to existing 802.11 agreements, neighboring access point AP keeps mourning in silence, and waits for network allocation vector NAV timer then, returns step (2) after timing terminates;
(4) neighboring access point AP is in transmission data, waits for the station replies acknowledge character ACK communicated with, and receives data generation interference to current access point AP1;
(5) current access point AP1 solves the data of needs from contaminated data:
(5.1) wireless data of transmission is converted to the frame format of cable network by neighboring access point AP by the protocol conversion module of MAC layer, sends current access point AP1 to by cable network, and current access point AP1 receives and these data of buffer memory;
(5.2) current access point AP1 sends the modulation system of signal and the frame format of neighboring access point AP transmission signal according to transmitting station STA1, physical-layer network coding method is adopted to carry out demodulation mapping to the contaminated wireless data signal received, and these data of buffer memory;
(5.3) current access point AP1 is according to the lead code in the data of step (5.1) buffer memory, and in step (5.2), data cached beginning pollutes position to utilize lead code correlation detection methods to determine;
(5.4) current access point AP1 is by data-signal direct step-by-step XOR after starting to pollute position of the data-signal of step (5.1) buffer memory and step (5.2) buffer memory, from pollution signal, recover former data-signal, realize the elimination to interference.
2. under intensive WLAN environment according to claim 1 based on the interference elimination method that many AP are collaborative, it is characterized in that, many AP are worked in coordination with and refer to and connected together with wired form by access controller AC between multiple access point AP, the data that neighboring access point AP sends by wire transmission to current access point AP.
3. under intensive WLAN environment according to claim 2 based on the interference elimination method that many AP are collaborative, it is characterized in that, whether access controller AC removes mourn in silence for controlling neighboring access point AP.
4. under intensive WLAN environment according to claim 1 based on the interference elimination method that many AP are collaborative, it is characterized in that, judge whether neighboring access point AP will send data in step (1), whether have data to arrive MAC layer according to high level: if had, then neighboring access point AP sends data; If no, then neighboring access point AP does not send data.
5. under intensive WLAN environment according to claim 1 based on the interference elimination method that many AP are collaborative, it is characterized in that, judges that can neighboring access point AP send data in step (2), carry out as follows:
(2.1) initialization system threshold value, if NAV timer is less than setting threshold remaining time, then neighboring access point AP just no longer sends data; If be more than or equal to setting threshold, perform step (2.2);
(2.2) neighboring access point AP removes the short frame of mourning in silence by there being alignment access controller AC to send a request, if now there has been other neighboring access point to ask releasing to be mourned in silence to AC, then access controller AC has replied this neighboring access point AP and does not allow releasing to mourn in silence; If no, then reply and allow releasing to mourn in silence, perform step (2.3);
(2.3) neighboring access point AP removes and mourns in silence, and starts to send data.Be greater than NAV timer remaining time when neighboring access point AP sends the data time used, then send data according to existing 802.11 protocol segmentations; When being less than or equal to NAV timer remaining time, directly send data.
6. under intensive WLAN environment according to claim 1 based on the interference elimination method that many AP are collaborative, it is characterized in that, in step (4), receiving station STA replys acknowledge character ACK, carries out as follows:
(4.1) the CTS frame of neighboring access point AP demodulation current access point AP1 transmission, obtains the moment D of transmitting station STA1 and current access point AP1 sign off, and this moment D is included in in the Frame of receiving station STA transmission; Record receiving station STA completed data receiver time engrave E, then when receiving station STA replys acknowledge character ACK, the timing of NAV timer is D+SIFS-E, SIFS is short frame period.
(4.2) moment that receiving station STA replys acknowledge character ACK to neighboring access point AP is D+SIFS.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105978653A (en) * | 2016-04-28 | 2016-09-28 | 西安电子科技大学 | Interference elimination method under overlapping basic service set |
| CN107666685A (en) * | 2016-07-28 | 2018-02-06 | 通用汽车环球科技运作有限责任公司 | Method for vehicle and multiple vehicle focus interference managements |
| WO2021078011A1 (en) * | 2019-10-25 | 2021-04-29 | 华为技术有限公司 | Wlan communication method, controller and ap |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103973610A (en) * | 2013-01-25 | 2014-08-06 | 华为技术有限公司 | Up data receiving method and device of wireless receiving and transmitting device |
| CN104168657A (en) * | 2013-05-20 | 2014-11-26 | 华为技术有限公司 | Communication method and communication device of same-frequency networking wireless local area network |
| US20150288428A1 (en) * | 2014-04-08 | 2015-10-08 | Electronics And Telecommunications Research Institute | Protocol for cooperation communication between access points in overlapped basic service set (obss) environment |
-
2015
- 2015-12-15 CN CN201510939127.4A patent/CN105491668A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103973610A (en) * | 2013-01-25 | 2014-08-06 | 华为技术有限公司 | Up data receiving method and device of wireless receiving and transmitting device |
| CN104168657A (en) * | 2013-05-20 | 2014-11-26 | 华为技术有限公司 | Communication method and communication device of same-frequency networking wireless local area network |
| US20150288428A1 (en) * | 2014-04-08 | 2015-10-08 | Electronics And Telecommunications Research Institute | Protocol for cooperation communication between access points in overlapped basic service set (obss) environment |
Non-Patent Citations (1)
| Title |
|---|
| 张琦，等: "基于QoS保障的密集WLAN多维资源分配算法", 《通信学报》 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105978653A (en) * | 2016-04-28 | 2016-09-28 | 西安电子科技大学 | Interference elimination method under overlapping basic service set |
| CN105978653B (en) * | 2016-04-28 | 2018-05-15 | 西安电子科技大学 | Interference elimination method under overlapping Basic Service Set |
| CN107666685A (en) * | 2016-07-28 | 2018-02-06 | 通用汽车环球科技运作有限责任公司 | Method for vehicle and multiple vehicle focus interference managements |
| CN107666685B (en) * | 2016-07-28 | 2021-12-07 | 通用汽车环球科技运作有限责任公司 | Method for managing interference between vehicle and multiple vehicle hot spots |
| WO2021078011A1 (en) * | 2019-10-25 | 2021-04-29 | 华为技术有限公司 | Wlan communication method, controller and ap |
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Application publication date: 20160413 |